Evaporative Emission Control System

Testing Charcoal Canister:

CHARCOAL CANISTER

1. Remove charcoal canister.
2. Visually inspect canister for cracks or other damage.
3. Check purge control valve for proper operation.
a. Apply approx. 50Kpa pressure (7.25 psi) to the port marked "V.C."
b. Check that there is no air leakage from the diaphragm.
c. Apply approx. 380mmHg (15"Hg) vacuum to the port marked "purge" and maintain.
d. Gradually apply vacuum to the port marked "V.C." If the purge port begins to open when vacuum at the "V.C." port is between approx. 40-80 mmHg (1.6"-3.2"Hg), the purge control valve is operating normally.
f. If problem is found, replace canister.

Vacuum Switching Valve (ECS System):

VACUUM SWITCHING VALVE

1. Remove VSV.
2. Connect vacuum pump to port B.
3. Block port A with finger tip and apply vacuum to port B. No vacuum should be felt at port A, and port B should be vented to the atmosphere (does not hold vacuum).
4. Energize solenoid by applying 12 volts DC.
5. Block port A with finger tip and apply vacuum to port B. Valve should hold vacuum until port A is opened.
6. Replace if defective.

NOTE: When re-installing VSV, be sure port B is connected to device and port A is connected to vacuum source. If connected improperly, a vacuum leak will result.

Check/Relief Valve:

CHECK/RELIEF VALVE

1. Remove valve.
2. Connect vacuum pump to side of valve leading to fuel tank.
3. Apply vacuum. Valve should hold a maximum of 20mmHg vacuum ( 0.8"Hg vacuum).
4. Disconnect vacuum pump, and connect it to the other port on valve.
5. Apply vacuum. Valve should hold a maximum of 40mmHg vacuum ( 1.6"Hg vacuum).
6. Replace if defective.